i2c: rcar: check master irqs before slave irqs

BugLink: https://bugs.launchpad.net/bugs/1776177

commit c3be0af1 upstream.

Due to the HW design, master IRQs are timing critical, so give them
precedence over slave IRQ.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Biju Das <biju.das@bp.renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

drivers/i2c/busses/i2c-rcar.c

@@ -432,19 +432,17 @@ static bool rcar_i2c_slave_irq(struct rcar_i2c_priv *priv)
 static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
 {
 	struct rcar_i2c_priv *priv = ptr;
-	irqreturn_t result = IRQ_HANDLED;
 	u32 msr;
 
-	if (rcar_i2c_slave_irq(priv))
-		goto exit;
-
 	msr = rcar_i2c_read(priv, ICMSR);
 
 	/* Only handle interrupts that are currently enabled */
 	msr &= rcar_i2c_read(priv, ICMIER);
 	if (!msr) {
-		result = IRQ_NONE;
-		goto exit;
+		if (rcar_i2c_slave_irq(priv))
+			return IRQ_HANDLED;
+
+		return IRQ_NONE;
 	}
 
 	/* Arbitration lost */
@@ -481,8 +479,7 @@ static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
 		wake_up(&priv->wait);
 	}
 
-exit:
-	return result;
+	return IRQ_HANDLED;
 }
 
 static int rcar_i2c_master_xfer(struct i2c_adapter *adap,